Review on cryogenic technologies for CO2 removal from natural gas

CO₂ in natural gas (NG) is prone to condense directly from gas to solid or solidify from liquid to solid at low temperatures due to its high triple point and boiling temperature, which can cause a block of equipment. Meanwhile, CO₂ will also affect the calorific value of NG. Based on the above reasons, CO₂ must be removed during the NG liquefaction process. Compared with conventional methods, cryogenic technologies for CO₂ removal from NG have attracted wide attention due to their non-polluting and low-cost advantages. Its integration with NG liquefaction can make rational use of the cold energy and realize the purification of NG and the production of by-product liquid CO₂. In this paper, the phase behavior of the CH₄-CO₂ binary mixture is summarized, which provides a basis for the process design of cryogenic CO₂ removal from NG. Then, the detailed techniques of design and optimization for cryogenic CO₂ removal in recent years are summarized, including the gas-liquid phase change technique and the gas-solid phase change technique. Finally, several improvements for further development of the cryogenic CO₂ removal process are proposed. The removal process in combination with the phase change and the traditional techniques with renewable energy will be the broad prospect for future development.     

低温等离子体对甲烷/氧反扩散火焰影响的实验研究

为探究低温等离子体对甲烷/氧反扩散火焰的影响,通过对同轴式喷注器环缝甲烷射流施加介质阻挡放电产生甲烷等离子体,综合采用多种测量手段实验研究了多种工况下该低温等离子体特性及火焰关键参数的变化。结果显示,放电击穿电压随混合比增大而减小,电流脉冲数量和幅值则随混合比增大而先增加后减小;甲烷等离子体呈灰白色,低电压下提高气体流量则放电有所减弱;受等离子体气动效应作用,放电后甲烷射流角有所增大,且电压越高射流角越大,增幅则逐渐减小,过高激励强度下射流发生失稳;等离子体通过改变燃料和氧化剂的掺混而影响甲烷/氧反扩散火焰的形态,使得火焰中心高度总体有所下降,特征长度缩短,释热强度则有所增加,其中小流量、低混合比条件下作用效果更明显;喷注器功率则随混合比上升而先增大后减小。     

全量程甲烷测量仪

介绍了设计矿用全量程甲烷测量仪的原理及硬件，软件组成，该仪器测量甲烷浓度范围为０－１００％。由于采用了新型单片机ＰＩＣ１６Ｃ５７和使用Ｉ＾２ＣＢＵＳ等串行Ｉ／Ｏ技术，使整机硬件结构得到简化。软件对热导元件非线性进行校正，提高了测量精度。     

GDX1包装机组小包封签检测器的改进

GDX1包装机组小包封签原装检测器仅能对X1小包机部分封签缺失的小包烟进行检测剔除。在GDX1包装机组的CH透明纸包装机部分加装了一套小包封签检测器,该检测器在小包烟进行透明纸封装后对烟包封签进行检测,避免了小包烟由X1小包机送往CH过程中,已粘贴的封签出现脱落而无法检测与剔除的现象。     

桉木SCMP浆CH3COOOH和H2O2漂白

对桉木磺化化机浆ＣＨ３ＣＯＯＯＨ、Ｈ２Ｏ２漂白的主要影响因素：药品用量、温度、时间、ｐＨ值、浆浓进行了研究，并对ＣＨ３ＣＯＯＯＨ、Ｈ２Ｏ２组合漂白程序进行了优化选择，得出了较佳工艺条件及较佳的组合程序Ｐａ－Ｐ及Ｐ－Ｐａ－Ｐ，同时对漂白前后纸浆红外光谱的变化进行了分析，初步探索了反应机理。     

改性废旧橡胶粉对水泥胶砂性能的影响

为了探究改性废旧橡胶粉(简称改性胶粉)对水泥胶砂性能的影响及作用机理,利用四因素三水平正交试验研究了改性胶粉掺入顺序、粒径、掺量及改性方法对水泥胶砂性能的影响,通过极差分析确定了最佳条件组合;通过热重分析、扫描电子显微镜、压汞试验研究了改性胶粉水泥胶砂CH含量、界面过渡区形貌及孔隙的变化.结果 表明:掺加改性胶粉可以降...